The press section is the heart of dewatering in a paper machine, turning a fragile wet web into a sheet stable enough for drying while protecting formation, bulk, and strength. Choices about fabrics, nips, roll covers, and loading strategies determine energy use, sheet moisture, and runnability. This guide presents the Top 10 Press Section Configurations for Paper Dewatering with practical engineering insight for mills and equipment designers. Each configuration explains strengths, ideal grades, and tuning levers for stability and efficiency. By understanding layout, pressure impulse, dwell time, and rewet control, you can push dryness while safeguarding quality and operational safety.
#1 Single nip press with suction pickup
A compact single nip press is a cost effective layout for slower machines and board grades, providing a straightforward path from forming to pressing with minimal draws. The suction pickup transfers the web reliably to a felted nip, where load and felt permeability dominate dryness. High felt void volume and sharp dewatering impulses can lift solids meaningfully without risking crush. Keys include precise crown control, consistent felt conditioning, and effective Uhle box vacuum to limit rewet. Use this configuration when space is constrained, sheet bulk is premium, and maintenance simplicity, accessibility, and stable runnability are top priorities.
#2 Double nip press for balanced dryness and runnability
Two consecutive nips raise dryness significantly before the dryer section, reducing steam demand while maintaining manageable loads. A first suction roll nip stabilizes transfer and removes free water, followed by a second plain or grooved roll nip tuned for consolidation and controlled compressibility. Alternating felt sides helps distribute compaction and improve surface properties while mitigating two sidedness. Critical controls include load split between nips, felt saturation limits, and short, guarded open draws between nips to prevent crushing or flutter. This configuration suits printing and writing grades where smoothness, tensile, and energy efficiency matter, and where capital budgets favor proven, serviceable components and spare parts availability.
#3 Tri nip press with large center roll
A tri nip press arranges three nips around a large center roll to maximize dewatering while preserving sheet support. The web remains under controlled wraps as it moves from pickup to the final nip, sharply reducing breaks. A typical sequence uses a suction pickup, a top or bottom felted pre nip, then a third consolidation nip against the center roll. Engineers tune nip sequencing, wrap angles, and felt conditioning to balance dryness against density and porosity. This layout is ideal for higher speeds, fine papers, and grades demanding clean sheet transfer, tight moisture profiles, and excellent dimensional stability.
#4 Double felted center nip for two sided dewatering
A double felted center nip places felts on both sides of the sheet, pulling water symmetrically and reducing two sidedness in density and roughness. Because both felts absorb, peak pore pressures are moderated, which can lower rewet tendency and improve impulse efficiency. Operators can bias loading and felt permeability to nudge top or bottom moisture independently. The design excels when both surfaces require comparable printability or coating holdout. Attention to felt compaction, cleaning showers, and Uhle box capacity is essential, since two felts demand higher vacuum throughput and disciplined conditioning to sustain stable, repeatable dryness gains.
#5 Single shoe press for extended nip dewatering
A shoe press replaces a rigid roll with a flexible belt and hydrostatic shoe, creating a long, gentle nip with high impulse at moderate peak pressure. Water has more time to migrate into the felt, raising dry content several points while limiting fiber crush and preserving bulk. Variable shoe zones let you shape pressure profiles to reduce edge wetness and optimize CD uniformity. Select high void volume felts, robust belt conditioning, and reliable seal water systems to prevent marking and heat buildup. This configuration is a powerful upgrade path for newsprint, linerboard, and packaging grades seeking energy savings and dryer bottleneck relief.
#6 Tandem shoe presses for maximum dryness before dryers
Placing two shoe presses in sequence boosts dryness to exceptional levels, often allowing speed increases or steam reductions without sacrificing strength. The first shoe targets free water and stabilization, while the second focuses on consolidation and final moisture profiling. Independent pressure zoning, felt selections, and belt cooling strategies prevent overheating and maintain felt receptivity. Engineers monitor nip saturation and vacuum capacity closely to avoid rewet between shoes. Tandem shoes shine on high speed board and packaging machines where dryer capacity limits production, and where improved bonding and caliper can be balanced with target bulk and stiffness.
#7 Pre press followed by main shoe for staged loading
A staged concept places a conventional or mini shoe pre press ahead of a main shoe, spreading the total pressure impulse across two controlled steps. The pre press evacuates easily removed water and stabilizes the sheet, allowing the main shoe to operate at lower peak pressure while maintaining impulse. This reduces density spikes and preserves formation. Operators tune the pre press load, felt permeability, and pickup geometry to feed an optimally conditioned web. Use this layout when sensitive grades need high dryness without over compaction, or when retrofitting existing frames that cannot accept two full size shoes in series.
#8 Press with transfer belt for closed draws and clean handoffs
A transfer belt bridges nips and reduces open draws, carrying the sheet from pickup through subsequent nips while shielding it from flutter and edge cracks. The belt can also act as an additional dewatering medium, accepting water and smoothing pressure entry. Benefits include improved threading reliability, fewer breaks, and cleaner edges that reduce wet end dirt carryover. Proper belt tension, tracking, and surface conditioning are critical to avoid barring and heat issues. This configuration fits fast machines where stable sheet support through the section is essential, and where compact layouts must minimize unsupported spans and operator interventions.
#9 Suction press layout for tissue bulk preservation
Tissue machines prioritize bulk and softness, so the press design emphasizes gentle water removal with controlled nip intensity. A suction press against a Yankee cylinder removes water while limiting caliper loss, and the felt is tuned for resilience and fast release. Vacuum levels, felt moisture targets, and nip dwell time are adjusted to protect creping potential and absorbency. Anti rewet devices at felt exit and disciplined showering preserve sheet temperature and cleanliness. This configuration succeeds where absolute dryness is secondary to tactile properties, and where stability at very high speeds is mandatory for safe, efficient operation.
#10 Closed press section with anti rewet and vacuum optimization
A closed press section integrates guards, transfer boxes, and controlled environments that limit misting, heat loss, and uncontrolled rewet. Key features include high capacity Uhle boxes, optimized save all geometry, grooved or blind drilled covers for water handling, and targeted anti rewet elements at nip exits. Vacuum setpoints are coordinated with felt saturation to prevent over drying the felt and starving the nip. Moisture profiling, edge trimming, and felt conditioning automation complete the system. This configuration is a versatile backbone for many grades, improving cleanliness, safety, and dewatering efficiency while supporting high speed threading and consistent runnability.